The present invention relates to a series of new 4-aminoquinazoline derivatives, to their salts and hydrates, to processes for preparing them and to their use in the treatment of various diseases affecting agricultural and horicultural plants.
Certain 4-aminoquinazoline derivatives are disclosed in Japanese Pat. No. 545936 and shown to be effective in the control of phytopathogenic fungi. We have now discovered a class of new 4-aminoquinazoline derivatives which have a broader and better fungicidal activity than do these known compounds against bacteria and fungi parasitic on agricultural and horticultural plants.
Our co-pending US Patent Application Ser. No. 910,117 filed May 30, 1978, U.S. Pat. No. 4,213,987, also discloses a series of fungicidal 4-aminoquinazoline derivatives having excellent fungicidal activity. However, we have surprisingly found that the compounds of the present invention have a significantly lower toxicity to fish than do the compounds of our co-pending Application. As worldwide concern over the pollution of the environment increases, it becomes more and more important that the impact of agricultural chemicals should be limited to the target section of the ecology and, in particular, that agricultural pest-killers should have a low toxicity to animals, plants etc other than the pests which they are designed to kill. Moreover, the low fish toxicity of the compounds of the invention enables these compounds to have a much broader spectrum of use; thus, for example, the compounds of the invention, are especially useful in the treatment of paddy-fields.